Investigating the role of oxygen tolerance in a [NiFe]-hydrogenase in bacterial competition. (360G-Wellcome-100188_Z_12_Z)

The oxygen tolerance of [NiFe]-hydrogenases is proposed to have a key role in bacterial virulence. Single site mutants of oxygen-tolerant Escherichia coli Hyd-1 will be generated and tested for key properties such as tolerance to oxidative and acidic stress using protein film electrochemistry. In addition to a Hyd-1 deletion strain of E. coli from the Keio collection, E. coli containing these variants of Hyd-1 shall be placed in competition experiments against the wild type strain to determine if those lacking, or with a mutated,Hyd-1 are at a competitive disadvantage. The competition experiments will be conducted in a chemostat in order to strictly control conditions such as pH, percentage of atmospheric hydrogen and percentage of atmospheric oxygen. Macrophage studies will be conducted on the mutant and wild type E. coli in order to determine how bacterial survival is impacted by the mutations created. Given success in these trials, the relevance of this work to human gut flora will be explored using in vivo experiments on a novel invertebrate animal model.